const d = new Date(-100000);
console.log(d.toISOString()); // 1969-12-31T23:58:20.000Z
console.log(d.toLocaleString()); // 1970/1/1 07:58:20

d.setTime(d.getTime() + 300000);
console.log(d.toISOString()); // 1970-01-01T00:03:20.000Z
console.log(d.toLocaleString()); // 1970/1/1 08:03:20
